The requirement of an angular adjustability of the wiper blade is increasingly imposed in view of the fact that windscreens more frequently are designed curved to minimize the air resistance coefficient of automotive vehicles. To adjust the angular position of the wiper blade, a multiplicity of solutions has been offered in which, on the one hand, the wiper blade itself is adjusted with respect to the wiper arm while, on the other hand, one end section of the wiper arm is rotated with respect to the remainder of the mounting section.
DE-OS 3 900 525 teaches to provide a means for fixing the wiper arm to the wiper spindle which is pivoted along with the wiper spindle, thereby also causing a reciprocating movement of the remainder of the wiper arm. In addition, the remainder of the wiper arm is rotatably arranged within the mounting means, with the remainder of the wiper arm during its oscillating movement being rotated by a corresponding crank control. The disadvantage of this arrangement is that the section of the wiper arm associated to the wiper spindle is divided into two oppositely movable parts requiring enhanced mechanical efforts. Moreover, the prior known construction regarding the rotating movement of the wiper arm permits only relatively short force levers.
FR 2 625 715 discloses a wiper arrangement in which the reciprocating pivotal movement of the wiper arm about the axis of the wiper spindle is superimposed by an additional reciprocating rotary movement of the wiper arm about the longitudinal axis thereof. The wiper arm is fixed to a control part, which by means of another component secured to the wiper spindle, is pivoted about the axis of the wiper spindle and at the same time is pivotally rotated by moving a control curve about the longitudinal axis of the wiper arm. The disadvantage of this solution resides in the bearing points of the control part which are exposed to very high loads because all forces transferred to the wiper arm travel exclusively through the bearing points (the bearing points are required to accommodate all counter-forces of the wiper arm).